Spring Cloud(二) 配置Eureka Client

前文回顾：

Spring Cloud(一）Eureka Server-单体及集群搭建

本节我们将创建两个Eureka Client，注册到上节中的Eureka Server中，一个作为服务提供方，一个作为服务调用方。

一.服务提供方（生产者）

1.pom中添加依赖

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/>
    </parent>
​
    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    </properties>
​
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
​
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

2.Application启动类中添加注解

• @EuableDiscoveryClient：就是一个自动发现客户端的实现

@SpringBootApplication
@EnableDiscoveryClient
public class ProducerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProducerApplication.class, args);
    }
}

3.配置文件

spring.application.name=spring-cloud-producer
server.port=9000
eureka.client.serviceUrl.defaultZone=http://localhost:8000/eureka/

4.提供服务

@RestController
public class HelloController {
​
    @RequestMapping("/hello")
    public String index(@RequestParam String name) {
        return "hello " + name + "，welcome to Spring Cloud";
    }
}

二.服务调用方（消费者）

1.pom中添加依赖

 <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yfy</groupId>
    <artifactId>consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>consumer</name>
    <description>Demo project for Spring Boot</description>
​
    <properties>
        <java.version>1.8</java.version>
    </properties>
​
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

2.Application启动类中添加注解

• @EnableDiscoveryClient :启用服务注册与发现

• @EnableFeignClients：启用feign进行远程调用

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class ConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConsumerApplication.class, args);
    }
}

3.配置文件

spring.application.name=spring-cloud-consumer
server.port=9001
eureka.client.serviceUrl.defaultZone=http://localhost:8000/eureka/
feign.hystrix.enabled=true

4.Feign调用实现

@FeignClient(name= "spring-cloud-producer",fallback = HelloRemoteHystrix.class)
public interface HelloRemote {
​
    @RequestMapping(value = "/hello")
    String hello(@RequestParam(value = "name") String name);
}

5.web层调用远程服务

@RestController
public class HelloController {

    @Autowired
    HelloRemote helloremote;

    @RequestMapping("/hello/{name}")
    public String index(@PathVariable("name") String name) {
        return helloremote.hello(name);
    }
}

三.测试

依次启动spring-cloud-eureka、spring-cloud-producer、spring-cloud-consumer三个项目

浏览器中输入：http://localhost:9001/hello/yfy

返回：hello yfy，welcome to Spring Cloud

4.负载均衡测试

将生产者的controller方法修改为

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@RestController
public class HelloController {

    @RequestMapping("/hello")
    public String index(@RequestParam String name) {
        return "hello " + name + "，welcome to Spring Cloud:product2";
    }
}

再启动一个生产者，端口为9003

浏览器中输入：http://localhost:9001/hello/yfy

第一次返回：hello yfy，welcome to Spring Cloud

第一次返回：`hello yfy，welcome to Spring Cloud:product2

不断的进行测试下去会发现两种结果交替出现，说明两个服务中心自动提供了服务均衡负载的功能。